Ekobot proves effective in removing weeds in onions

Despite this, Dutch onion grower Gijs Krol, who tested the Ekobot, did not manage to save on his herbicide use, something he had hoped for in advance. “This is partly due to the high weed pressure in this area and the fact that I set the bar very high.”

First practical trial with Ekobot

The trial at Krol Potatoes was the first practical trial of the weeding robot outside Sweden, where Ekobot is based. “This company started developing this robot for onion cultivation a few years ago,” says Jeroen de Bruin, researcher in precision agriculture at Wageningen University & Research (WUR). “This is because the package of herbicides is becoming more and more limited. Growers worldwide are therefore diligently looking for alternatives. In addition, the onion is a relatively difficult crop to identify. The idea was that if you succeed in detecting and weeding out weeds in onions, you can easily copy the principle to other crops.”

Meanwhile, a pre-production series of the Ekobot is available, which was previously tested by an onion grower in Sweden. Ekobot, however, was keen to carry out trials in other countries too, and approached WUR for help. “We then brought them into contact with Gijs Krol of Krol Potatoes. This eventually resulted in a pilot project. It started at the beginning of May and ran for four weeks.”

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Swatting away weeds

The robot, which moves autonomously over the field, has a track width of two metres. On Krol’s fields, it could treat seven rows in one pass. “The unit contains seven colour cameras, each of which scrutinises a row and looks at the plants from the side. Based on Artificial Intelligence, the robot knows what an onion plant looks like, so it can also detect weeds. The ‘fingers’ on the robot then swat or push the weeds away”, explains De Bruin.

The Ekobot has been developed to keep ten hectares of onions weed-free. On average the weeding unit can manage three hectares a day. On Krol’s farm the Ekobot was tested on an area of 2.5 hectares.

No major obstacles

According to the researcher, it has become clear that the robot does what it is supposed to do: it recognises and removes almost all weeds and does virtually no damage to the crop. “So basically the machine works. Although setting up the robot still requires some programming knowledge, I don’t see any major obstacles to a further roll-out.”

It is also nice that the robot does not only remove weeds in the rows, but also between the plants

Gijs Krol shares that opinion and also points out that the Ekobot manages to tackle most of the weeds. “It is also nice that the robot does not only remove weeds in the rows, but also between the plants. We did notice that it had some trouble removing weeds of four centimetres or more; these were often rooted too deep. The robot often needed two passes to remove them. Maybe this would have been less of a problem if we could have started the pilot earlier, and tackled the weeds more at the base.”

The farmer had hoped in advance to have to use less herbicides on the field were Ekobot was weeding. However, that was not the case: Krol used as many herbicides as during other seasons and also sprayed a contact herbicide.

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Opportunities to reduce spraying

“However, this was not because the robot was not doing its job properly. The weed pressure here on the sandy soils is extremely high. Therefore, you cannot take any risks. I also set the bar very high personally; I want my field to be completely clean. For growers on clay soils, where weeds are less of a problem, the Ekobot certainly offers opportunities to reduce spraying.”

Potential for organic growers

Krol also sees potential for organic growers, who are reliant on manual weeding. And he himself may want to set up a follow-up trial in the future. “After all, the social pressure to work more sustainable is increasing; we will have to do ‘something’. It would be nice if in the future the robot also offers possibilities to weed onions in a later stage of growth. In short: the principle of Ekobot works, but the specific cultivation situation determines its potential.”

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Great interest in Ekobot

According to Jeroen de Bruin, there is great interest in the Ekobot. “Organic growers in particular are interested in the Ekobot, which can be leased for around € 30,000 a year. In addition, the possibilities of using the robot in other crops are already being explored. Sugar beet and chicory, among others, are in the picture, because in these crops fewer substances are used. In short: we will certainly hear more about this weeding robot.”